Yukawa, a book-smart but socially inept scientist, solves complex crimes using his in-depth scientific knowledge, and makes hypotheses and conclusions based only on the law of physics.

In real life, the Japanese mega-star forms his extensive world views from the projects he works on. For example, Fukuyama learned about how to strike a balance between environmental conservation and economic development after working on his latest movie, Midsummer Equation.

The actor recently came to Hong Kong to promote the film, the second movie instalment based on the original Galileo series. The first season of the show aired in 2007, gaining huge popularity. In 2008, Suspect X, the first series-turned-movie was released.

While in town, Fukuyama shared some of his new views.

"Humans, as a collective race, need development, and it's a choice that people have to make," Fukuyama says. "But you can't lean all to one side. You need to protect the environment as well."

Midsummer Equation is a detective story set in the coastal town of Harigaura. Its storyline revolves around a tussle between a money-driven developer and environmental conservation groups.

Yukawa arrives at Harigaura as the consultant for an energy titan. His job is to gauge the environmental impact of a potential new oil drilling plant.

Then, as in the Galileo series episodes, someone is murdered, and Yukawa is called upon to help with the investigation.

Fukuyama says he was captivated by the conflicts between the oil company and the local residents in the film.

While the aim of the corporation is to pump oil from the sea and maximise profits, locals radically protest the plan, as they believe it will damage the coastline and harm the native animal species.

As if matters aren't complicated enough, there are also local residents who support the drilling because they believe it will help boost the economy in the secluded town.

Fukuyama - who has spent some time working on documentaries in remote, abandoned places - doesn't think it's wise for people to make one-sided judgments and say categorically that the environment should be protected at the expense of development.

"The question is, no matter how much most people claim they like nature, if they are put in places that have virtually nothing, can they survive?" For example, daily actions as minor as switching on an air conditioner are damaging to the environment, he says.

"But as the world becomes more and more developed, we also have to be concerned about the environment and to try to [preserve it]," says Fukuyama.

He says he enjoys nature, but he also enjoys being able to live in a well developed, tightly connected city. His suggestion is to strike the right balance through the use of technology.

"If both sides have to co-exist, technology and scientific research will play a big role," he says.

The actor says shooting Midsummer Equation was very enjoyable, as all the actors were very professional. He especially praises nine-year-old actor Hikaru Yamazaki, with whom he shares many moments on camera. Fukuyama says Hikaru is very talented, always delivering what the director wanted.

While this is his first promotional trip to our city, Fukuyama wants to come back for another professional, though different, visit.

"I would love to hold a concert [here]," says Fukuyama, who was a well-respected J-pop singer in the '90s, before taking up acting.

Until his return, detective drama fans can catch him in the film, and on the small screen in the second season of Galileo, on TVB Jade every Saturday at 10pm.